Teaching 3D objects

Information, resources and lesson ideas for teaching 3D objects

Key ideas

• 3D objects have three main characteristics: edges, vertices, and faces.
• The world is full of 3D objects! Shapes with flat faces, straight edges and vertices are called polyhedra, as they have polygons for faces.
• There are five Platonic solids where the faces are all regular polygons: the tetrahedron, cube, octahedron, dodecahedron and icosahedron.
• Prisms - where each of two identical ends is joined by rectangles - are also important 3D objects. A Toblerone is shaped like a triangular prism.
• Pyramids are different from prisms and the Platonic solids, because they have a polygon for a base, then triangles connecting the base to the apex.
• Non-polyhedra include the cylinder and the sphere, but don't forget the cone and the torus!

Activities

• Make 3D objects from nets (see below for good sites with nets) - colour in the vertices and number the faces before you fold them up!
• Use the nets to help learn about Euler's Law
• Discuss the key vocabulary of 3D objects as noted above
• Find 3D objects in the classroom and beyond.
• Classify 3D objects according to their characteristics, including faces, edges, vertices, but also whether they roll, bounce, stack etc.
• Match pictures of shapes to their names, e.g. using this
  

  3D shapes matching activity.pdf
  

  • Details
  • Download
  • 264 KB

Web sites

• Collections of nets: senteacher.org and lots of amazing (complex) ones at http://www.korthalsaltes.com/
• BBC KS1 Bitesize Shape Lab
• Platonic solids at mathsisfun.com with a great animation that lets you spin and "explode" the solids (includes nets)
• NCTM has a similar tool called Illuminations: Geometric Solids
• BGfL page for 2D shapes and 3D objects, great pictures, nets and information for lots of shapes and objects
• How to Draw 3D shapes - this set of instructions might help with your drawing if you are not confident.
• Isometric (and other types of) graph paper - useful for drawing 3D shapes
• PrintFreeGraphPaper has isometric paper
• If you want to demonstrate drawing using isometric paper you may find the Isometric Drawing Tool at NCTM useful, although I think it is a bit clunky.
• The Geometry Manipulatives NLVM page including Platonic Solids, their duals and lots of other 2D and 3D virtual manipulatives

YouTube

• Cute song for young kids about 3D shapes
• There are some interesting videos by Alan Sturgess showing how to use isometric paper to draw 3D objects: Isometric Drawing and Isometric Writing
• A fun stop motion animation using isometric dot paper.
• This video from Numberphile about Platonic solids is interesting, but possibly too fast moving for children.

Don't forget if you are a Google Earth fan that the concept of 3D can be illustrated by turning on and off 3D buildings at famous or well known places with 3D buildings.

Resources